Inflammatory bowel disease includes chronic gastrointestinal disorders characterized by infiltration of inflammatory cells into the mucosa of the digestive tract. Ulcerative colitis and Crohn's disease are two prevalent conditions among them.
Ulcerative colitis takes place in the large intestine (i.e., colon). The inner lining of the disordered intestine becomes inflamed and develops ulcers.
Crohn's disease most commonly affects the end of the small intestine (i.e., terminal ileum) and parts of the large intestine. It causes inflammation that extends much deeper into the layers of the intestinal wall than ulcerative colitis.
Both ulcerative colitis and Crohn's disease are attributed to dysregulation of pro-inflammatory cytokine, including TNFα and IL-1β. See, e.g., McClane S. J. et al., Journal of Parenteral and Enteral Nutrition 23, 1999. Therapeutic agents have been developed based on down-regulation of pro-inflammatory cytokine. For example, 5-aminosalicylic acid, an inhibitor of TNFα signaling events, has been used to treat ulcerative colitis. See, e.g., Therapeutic Immunology Ed. Austen, K. F., Blackwell Publishing, 2001, 159-167. However, most inflammatory bowel disease therapeutics have limited efficacy or significant side effects.
There is still a need to develop more effective therapeutic agents for treating inflammatory bowel disease.